Woolly Mammoths and Rhinos Ate Flowers

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Woolly mammoths, rhinos and other ice age beasts may have munched
on high-protein wildflowers called forbs, new research suggests.

And far from living in a monotonous grassland, the mega-beasts
inhabited a colorful Arctic landscape filled with flowering
plants and diverse vegetation, the study researchers found.

The new research "paints a different picture of the Arctic,"
thousands of years ago, said study co-author Joseph Craine, an
ecosystem ecologist at Kansas State University. "It makes us
rethink how the vegetation looked and how those animals thrived
on the landscape."

The ancient ecosystem was detailed today (Feb. 5) in the journal
Nature.

Pretty landscape

In the past, scientists imagined that the now-vast
Arctic tundra was once a brown grassland steppe that teemed
with wooly mammoths, rhinos and bison. But recreations of the
ancient Arctic vegetation relied on fossilized pollen found in
permafrost, or frozen soil. Because grasses and sedges tend to
produce more pollen than other plants, those analyses produced a
biased picture of the landscape. [ Image
Gallery: Ancient Beasts Roam an Arctic Landscape ]

To understand the ancient landscape better, researchers analyzed
the plant genetic material found in 242 samples of permafrost
from across Siberia, Northern Europe and Alaska that dated as far
back as 50,000 years ago.

They also analyzed the DNA found in the gut contents and
fossilized poop, or coprolites, of eight Pleistocene
beasts — woolly mammoths, rhinos, bison and horses — found in
museums throughout the world.

The DNA analysis showed that the Arctic at the time had a varied
landscape filled with wildflowers, grasses and other vegetation.

And the shaggy
ice age beasts that roamed the landscape took advantage of
that cornucopia. The grazers supplemented their grassy diet with
a hefty helping of wildflowerlike plants known as forbs, the
stomach content analysis found.

These forbs are high in protein and other nutrients, which may
have helped the grazers put on weight and reproduce in the
otherwise sparse Arctic environment, Craine told Live Science.

Vanishing wildflowers

Between 10,000 and 15,000 years ago, forbs declined in the
Arctic, study co-author Mary E. Edwards, a physical
geographer at the University of Southampton in England, wrote in
an email.

Though it's not exactly clear why, "we do know from much other
evidence that the climate changed
at this time," Edwards said.

The ice age was ending and warmer, wetter weather was prevailing.
That climate "allowed trees and shrubs to flourish and these
would have outgrown forbs — by shading them for example," Edwards
said.

It's also possible that the vanishing of these high-protein
plants hastened the extinction of ice age beasts such as the
woolly
mammoth. For example, grasslands may have been delicately
balanced, with poop from the grazers nourishing the plants, which
in turn kept the animals alive. If a big jolt in climate
disrupted one part of the chain — for instance by depleting the
forbs — that may have led the whole system to collapse, Edwards
speculated.

The findings also raise questions about modern grazers such as
bison, Craine said. If the ancient beasts dined on forbs, it's
possible these wildflowerlike plants play a bigger role in the
diet of modern bison as well, he said.